[C] Analisi codice

[Haki96]

#include <windows.h>#include <gl/gl.h>


LRESULT CALLBACK WindowProc(HWND, UINT, WPARAM, LPARAM);
void EnableOpenGL(HWND hwnd, HDC*, HGLRC*);
void DisableOpenGL(HWND, HDC, HGLRC);




int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nCmdShow)
{
    WNDCLASSEX wcex;
    HWND hwnd;
    HDC hDC;
    HGLRC hRC;
    MSG msg;
    BOOL bQuit = FALSE;
    float theta = 0.0f;


    /* register window class */
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.style = CS_OWNDC;
    wcex.lpfnWndProc = WindowProc;
    wcex.cbClsExtra = 0;
    wcex.cbWndExtra = 0;
    wcex.hInstance = hInstance;
    wcex.hIcon = LoadIcon(NULL, IDI_APPLICATION);
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wcex.lpszMenuName = NULL;
    wcex.lpszClassName = "GLSample";
    wcex.hIconSm = LoadIcon(NULL, IDI_APPLICATION);;




    if (!RegisterClassEx(&wcex))
        return 0;


    /* create main window */
    hwnd = CreateWindowEx(0,
                          "GLSample",
                          "OpenGL Sample",
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT,
                          CW_USEDEFAULT,
                          256,
                          256,
                          NULL,
                          NULL,
                          hInstance,
                          NULL);


    ShowWindow(hwnd, nCmdShow);


    /* enable OpenGL for the window */
    EnableOpenGL(hwnd, &hDC, &hRC);


    /* program main loop */
    while (!bQuit)
    {
        /* check for messages */
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
        {
            /* handle or dispatch messages */
            if (msg.message == WM_QUIT)
            {
                bQuit = TRUE;
            }
            else
            {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
        }
        else
        {
            /* OpenGL animation code goes here */


            glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
            glClear(GL_COLOR_BUFFER_BIT);


            glPushMatrix();
            glRotatef(theta, 0.0f, 0.0f, 1.0f);


            glBegin(GL_TRIANGLES);


                glColor3f(1.0f, 0.0f, 0.0f);   glVertex2f(0.0f,   1.0f);
                glColor3f(0.0f, 1.0f, 0.0f);   glVertex2f(0.87f,  -0.5f);
                glColor3f(0.0f, 0.0f, 1.0f);   glVertex2f(-0.87f, -0.5f);


            glEnd();


            glPopMatrix();


            SwapBuffers(hDC);


            theta += 1.0f;
            Sleep (1);
        }
    }


    /* shutdown OpenGL */
    DisableOpenGL(hwnd, hDC, hRC);


    /* destroy the window explicitly */
    DestroyWindow(hwnd);


    return msg.wParam;
}


LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg)
    {
        case WM_CLOSE:
            PostQuitMessage(0);
        break;


        case WM_DESTROY:
            return 0;


        case WM_KEYDOWN:
        {
            switch (wParam)
            {
                case VK_ESCAPE:
                    PostQuitMessage(0);
                break;
            }
        }
        break;


        default:
            return DefWindowProc(hwnd, uMsg, wParam, lParam);
    }


    return 0;
}


void EnableOpenGL(HWND hwnd, HDC* hDC, HGLRC* hRC)
{
    PIXELFORMATDESCRIPTOR pfd;


    int iFormat;


    /* get the device context (DC) */
    *hDC = GetDC(hwnd);


    /* set the pixel format for the DC */
    ZeroMemory(&pfd, sizeof(pfd));


    pfd.nSize = sizeof(pfd);
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_DRAW_TO_WINDOW |
                  PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 24;
    pfd.cDepthBits = 16;
    pfd.iLayerType = PFD_MAIN_PLANE;


    iFormat = ChoosePixelFormat(*hDC, &pfd);


    SetPixelFormat(*hDC, iFormat, &pfd);


    /* create and enable the render context (RC) */
    *hRC = wglCreateContext(*hDC);


    wglMakeCurrent(*hDC, *hRC);
}


void DisableOpenGL (HWND hwnd, HDC hDC, HGLRC hRC)
{
    wglMakeCurrent(NULL, NULL);
    wglDeleteContext(hRC);
    ReleaseDC(hwnd, hDC);
}

Qualche buon uomo potrebbe dirmi quale parte del codice si modifica per cambiare figura usando funzioni diverse ?

[oregon]

Che vuoi dire?